Basic Neuron Questions
k.p.collins at worldnet.att.net%remove%
Sat Apr 12 23:52:12 EST 2003
METHOD proposal below.
"KP-PC" <k.p.collins at worldnet.att.net%remove%> wrote in message
news:Qj3ma.26220$cO3.1906450 at bgtnsc04-news.ops.worldnet.att.net...
| Hi Didier.
| "Didier A. Depireux" <didier at tango.isr.umd.edu> wrote in message
| news:b79jlr$c5a$1 at grapevine.wam.umd.edu...
| | r norman <rsnorman_ at _comcast.net> wrote:
| | > On Thu, 10 Apr 2003 15:44:25 +0000 (UTC), "Didier A. Depireux"
| | > <didier at rai.isr.umd.edu> wrote:
| | > [...]
| | > Certainly there are specific cases
| | > where timing of nerve activity,
| | > even to the sub-millisecond level, is critical.
| | That is true, and typically it's periferal.
| | For instance, fibers of the auditory nerve
| | can code pure tones' phase up to about
| | 2 kHz (more or less depending on who
| | you read). This implies an accuracy in
| | firing time in the 100 microsec range.
| | By the time you get to cortex, though
| | (which I thought was the original question),
| | things are a lot more sluggish and noisy.
| | Present the same stimulus 20 times and
| | you will never get 20 times the same
| | response, in most parts of cortex.
| The same thing never happens in the
| [global] nervous system twice
| because mocroscopic trophic
| modifications occur as a result of the
| activation that occurs within nervous
| systems. Via ongoing convergence
| upon TD E/I-minimization the global
| system is =always= 'learning' - analyses
| must converge upon rigor with respect
| to such. When this is accomplished,
| the cortical activation differentials that
| you point out will become a [the?]
| primary means of describing the
| underpinning "micro-mods" - that is,
| activation differentials will be
| referred back to neural Topology
| differentials [including the
| "supersystem configuration" dynamics
| that are discussed in AoK, Ap5].
This's a 'hard' problem, but it's long seemed to me that everything
necessary to =begin= making significant progress towards its
resolution has been available.
It does require substantial computing capacity, however, and, in
addition, requires the development of non-destructive, but
nevertheless, invasive experimental techniques.
The research program entails the use of such non-destructive
[electrode-implantation, etc.] techniques, and long-term use of
scanning [PET, fMRI, 2-DG, etc.] in conjunction with =simultaneous=
electrode-recording and synchronized video, audio, treadle, etc.,
recording of behaviora; functioning. Synchronizization of all
recording 'tracks' is of =paramount= importance.
The other experimental-design consideration is to establish a
controlled experimental environment [literally a self-contained,
'playing field' - the richer the better, and, of course, as wired-up
with sensors to the max practical degree] for the subjects to
All interaction with the subject animals must be optimized with
respect to prolonging the survival of the subjects in as 'normal' a
way as is possible. With respect to such, it'd be nice to have the
electrode data transmitted by small worn transmitters, which'd free
the subjects from being 'tethered' by the recording data wires
[caveat: can such transmitters, and their batteries, be constructed
small enough to actually allow some degree of 'normalcy' in the
subjects' behaviors?] Such 'telemetry' would, for instance, allow
subjects to negotiate tub mazes, to burrow, bass under and through
features of the experimental 'playing field", and, most-importantly,
=interact= with other subjects - all while their data streams are
being recorded and archived.
After assuring that the electrode implants are functional, and that
all of the apparatus is properly synchronized, experimenters want to
=just= let the subjects manifest 'normal' behavior in interaction
with the experimental environment.
The goal is to 'just' record and archive the synchronized data-trains
that the experiment yields - so, the longer each 'trial' the better.
There are, therefore, three main 'phases' in this experimental
1. Design of the 'playing-field' - as rich as possible - gathering
the 'sensors' - as rich as possible - and developing methods to
assure their synchronization. Multiple instances of each type of
recording device must be incorporated, both to guard against device
failure, and to allow for 'normal' service [cassette and battery
replacement, etc.] A protocol must be developed to handle changing
the batteries in the transmitters if subject telemetry is used -
rigorously-standardised [well=practiced] procedures. This'll minimize
extraneous impacts of 'handling' within the data streams that are
2. Implantation decisions and implementation.
3. This's where the 'Treasure' will be mined. In-depth data analysis
of each synchronized data trace with respect to every other data
trace. Yhis can be done long-term, over and over again with respect
to various questions, etc. The data are a 'world' of their own, into
which researchers can 'enter' enduringly.
This method has the advantage that the data it produces is archivable
and sharable - just think of the worth inherent in such. Data from
any trial could be made available to other researchers.
Prediction: TD E/I-minimization traces extracted from the data will
be observable, and will cross-correlate the variability to which
Didier referred in his prior post, quoted above.
The subjects won't even have to be 'sacrificed' because, as
experience develops with this experimental approach, it will be
realized that electrode-placement can be read directly from the
synchronized data streams :-]
NDT of NDT ["Non-Destructive-Testing' of "Neuroscientific Duality
Cheers, K. P. Collins
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